2: Kinetic particle theory

Question 1

Kinetic particle theory

Answer 1

• states that all matter is made up of tiny particles and these particles are in constant random motion

Question 2

Arrangement and movement of particles in solid

Answer 2

• particles are very closely packed in an orderly manner
• they vibrate and rotate about their fixed positions
• have very low kinetic energy
• particles experience strong attractive forces, so a lot of energy is needed to break up regular arrangement
• solid have a definite volume and shape

Question 3

Arrangement and movement of particles in liquid

Answer 3

• particle spacing in liquids is larger than solids
• attractive forces are less strong
• arrangement is disorderly & they have low kinetic energy
• particles slide past one another freely throughout
• liquid has definite volume, but no definite shape

Question 4

Arrangement and movement of particles in gases

Answer 4

• particle spacing between particles is very large
• attractive forces between particles are very weak
• particles are found very far apart in a disorderly manner
• particles move quickly & randomly and any direction
• they have high kinetic energy
• gas has no definite volume and shape

Question 5

Heating curve & cooling curve

Answer 5

• too long, it is in the notebook

Question 6

Expansion of solid

Answer 6

• when a solid is heated at temps below melting point, particles cannot spread out freely as they are strongly attached to one another
• particles vibrate more quickly about their positions but with slightly wider spacing than before
• solid has undergone expansion

Question 7

Contraction of solid

Answer 7

• when solid is cooled, thermal energy is transferred from particles to surrounding
• particles possess less kinetic energy, so they vibrate more slowly and come closer than before
• solid has undergone contraction

Question 8

Sublimation

Answer 8

• change directly from solid to gas
• thermal energy from surroundings is transferred to solid, resulting in converting from solid to gas
• temp remains constant until all the substance is in gaseous state

Question 9

Vapour deposition

Answer 9

• from gas to solid w/o turning to liquid
• temp remains the same/constant until all the gas becomes solid
• particles in gas are cooled until they slow down and arrange themselves directly into the solid state
• ex: when iodine vapour comes into contact wither a cold glass surface, iodine crystals are formed

Question 10

Diffusion

Answer 10

• the net movement of particles from a region of higher concentration to a region of lower concentration

Question 11

What affects rate of diffusion

Answer 11

1. Temperature: as temp increase, particles have more thermal energy 👉 more kinetic energy 👉 they diffuse faster
2. Particle mass: when particle mass increase, rate of diffusion decrease since more KE is required for particles to move at the same speed